Point Design

Do I need to retrofit my home?

Jay Hosseinzadeh, PE, SE — Thu, 18 Feb 2016 21:14:20 +0000

Preparing your home from earthquake now is very important. There are certain ways to know if your home is in need of seismic retrofit. One way is to ask yourself 5 questions that are listed below, if your answer is yes to any of the questions, then you should consider retrofitting your home.

1-Was it built prior to 1985? Homes built prior to 1985 are typically more vulnerable to earthquake damages.

2-Is it built on a raised foundation? Homes that are not built on concrete slab. they typically have crawl space.

3-Is it built on a hillside ? Built on hillside have usually raised foundation meaning posts and cripple walls are built at different heights.

4- Is it in an area prone to earthquakes? You can find that out by calling your local building department.

5- Do I have a garage? The narrow walls on either side of the walls on either side of the garage door must be carefully designed to resist earthquake forces, if there is a living space above it. Because these rooms add weight that garage must support.

Pisa Tower Still Leaning!

Jay Hosseinzadeh, PE, SE — Fri, 29 Jan 2016 01:31:52 +0000

I recently traveled to Italy and as a Structural engineer I found Pisa tower very interesting. The Tower of Pisa (Torre di Pisa) is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its unintended tilt. The tower’s tilt began during construction, caused by an inadequate foundation on ground too soft on one side to properly support the structure’s weight. The tilt increased in the decades before the structure was completed, and gradually increased until the structure was stabilized (and the tilt partially corrected) by efforts in the late 20th and early 21st centuries.
It looks like the leaning Tower of Pisa will keep on leaning, stably, awhile longer. More than dozen years after major foundation work, the imperfect edifice hasn’t increased its lean. In fact, civil engineer John Burland of Imperial College London says his international team has succeeded in straightening the marble bell tower by 19 inches, reducing its angle of incline by about 10 percent, and slowing its once steady creep to nearly nothing.
It wasn’t easy. Built from 1173 to 1370 on silt and clay, the eight-story, 182 foot-tall tower resisted many efforts to stabilize it. What finally worked was a soil-removal process called under-excavation and the addition of wells to regulate groundwater. the chief fear now ? A big earthquake. “Absent that,” says Burland ” I’d be very surprised indeed if we see it lean significantly again.”

Who should pay for Seismic Retrofitting of Vulnerable buildings?

Jay Hosseinzadeh, PE, SE — Mon, 12 Oct 2015 19:48:24 +0000

Last week, Los Angeles city council voted unanimously to require mandatory retrofitting of two types of buildings which are most vulnerable in a major earthquake.
There are at least 13,000 wooden apartments and more than 1,000 concrete buildings across Los Angeles that city leaders want retrofitted. The cost of retrofitting those buildings varies widely. Strengthening wooden apartments with weak first floors could range from $60,000 to $130,000. Upgrading larger concrete buildings will probably runs into the millions.
Wooden “soft-story” apartments have a history of failing during big quakes. Sixteen people were killed when one such building pan-caked in the 1994 Northridge earthquake.

In 1971, the Sylmar earthquake brought down several concrete structures, killing 52.

Owners have to find a way to pay for those costly retrofits, but figuring out how to pay has not been easy. Under this ordinance, wooden buildings would have to be retrofitted within seven years; concrete structures would be retrofitted within 25 years.
I feel that retrofitting of vulnerable buildings benefits many people, businesses and communities. Therefore, I think many resources should be available to the building owners so that they can comply with retrofitting ordinances. Those resources could include low-interest loans, property tax, State and Federal income tax breaks to the owners who retrofit. I welcome your opinion.

Seismic Retrofitting

Jay Hosseinzadeh, PE, SE — Thu, 24 Sep 2015 22:55:56 +0000

We at Point Design, Inc. congratulate Los Angeles Mayor Eric Garcetti for initiating the "Resilience by Design" a program to address the retrofitting of the city's most earthquake vulnerable buildings, water and communication infrastructure. Two types of most vulnerable building types requiring retrofitting are identified as "Soft-First-Story" and "non-ductile reinforced concrete" buildings. It is crucial to make Los Angeles a safer city by retrofitting those vulnerable buildings protecting the public, tenants, building owners, and the economical base of the region. Selecting experienced retrofitting firm is critical to success of any project. Experienced engineering firm can save money and time on preparation of plans and construction. As a southern California based structural engineering firm we would like to offer our services and assistance to managers and owners of those type of buildings.
Please contact us for free consultation.

Berkeley Balcony Collapse

Jay Hosseinzadeh, PE, SE — Mon, 13 Jul 2015 16:42:14 +0000

My deepest sympathy and heartfelt condolences to the family of those young students who lost their precious lives in the tragic collapse of a four-story balcony in an apartment building in Berkeley, CA. As a Structural Engineer and father of a young college students I can feel the pain this unfortunate event have brought upon the families and the community. My older son graduated from the University of California at Berkeley just two years. So, I have developed a special bond to UC Berkeley and I still consider myself a Cal Dad. It’s ironic that this tragedy would happen only a couple of blocks away from the university campus where it houses one of the finest schools for civil engineering. I don’t know the cause of the failure first hand, I have not investigated it personally. Typically residential balconies of these types are designed for a live load of 60 pound per square foot (psf) in accordance with the building codes. My recommendation is to increase the design live load to 100 psf and make an amendment to the existing building codes expeditiously. Additionally I recommend establishing a special design criteria for overhang balconies with regards to floor joists sizes, back span length and proper sealing to prevent moisture or water penetration. Please feel free to email us with all your comments.